I just pulled the head off my '01 650R in order to get the valve guides replaced. (see Blowing Blue post of Aug. 6). Thanks to the people who responded. As I removed the carb I found a brass bolt that goes from the outside to the insde of the carb throat on the upstream side. It is at the 11 o'clock position. Any idea what it is for? Would a Scottoiler be able to use the vacuum produced here?